External preparation for skin

ABSTRACT

The present invention provides an external preparation for skin which contains 5-aminolevulinic acids as active components and which is excellent in skin-beautifying effects such as prevention/amelioration of skin roughness, dry skin, wrinkles, sagging and flecks of skin, and improvement of turnover of corneum; and in an ameliorating effect on skin diseases such as atopic dermatitis. An external preparation for skin which contains one or more compounds selected from the group consisting of 5-aminolevulinic acid, its salt and a derivative of them; and an iron compound; as active components, is used.

TECHNICAL FIELD

The present invention relates to an external preparation for skin whichis excellent in skin-beautifying effects such as prevention/ameliorationof skin roughness, dry skin, wrinkles, sagging and flecks of skin, andimprovement of turnover of corneum, and an external preparation for skinwhich is excellent in an ameliorating effect on skin diseases such asatopic dermatitis, more particularly, to an external preparation forskin wherein 5-aminolevulinic acids and an iron compound are used incombination.

BACKGROUND ART

Conventionally, external preparations for skin have been developed,which focused on prevention and amelioration of skin roughness. Examplesof such external preparations for skin include: skin externalpreparations for ameliorating skin roughness which contains alum,calcium salt and magnesium salt (see Japanese Laid-open PatentApplication No. 2004-284962), and an agent for preventing/amelioratingskin roughness which consists of N-α-benzoyl-L-arginine,N-α-benzoyl-L-arginine ethyl ester or salt of N-α-benzoyl-L-arginineethyl ester (see Japanese Laid-open Patent Application No. 2000-281556).

In addition, it has been known that 5-aminolevulinic acids are used asherbicides (for example, see Japanese Laid-open Patent Application No.08-081322), plant growth regulators (for example, see Japanese Laid-openPatent Application No. 07-53487), external preparations for head (forexample, see Japanese Laid-open Patent Application No. 11-116446), etc.

However, an external preparation for skin for making beautiful skinwhich contains 5-aminolevulinic acids and the effects of5-aminolevulinic acids on skin roughness, etc., have not been known.

-   Patent Document 1: Japanese Laid-open Patent Application No.    2004-284962-   Patent Document 2: Japanese Laid-open Patent Application No.    2000-281556-   Patent Document 3: Japanese Laid-open Patent Application No.    08-081322-   Patent Document 4: Japanese Laid-open Patent Application No.    07-53487-   Patent Document 5: Japanese Laid-open Patent Application No.    11-116446

DISCLOSURE OF THE INVENTION An Object to be Attained by the Invention

Though it has been known that 5-aminolevulinic acids are used asherbicides, plant growth regulators, external preparations for head,etc., an external preparation for skin for making beautiful skin whichcontains 5-aminolevulinic acids and the effects of 5-aminolevulinicacids on skin roughness, etc., have not been known. The object of thepresent invention is to provide an external preparation for skin whichcontains 5-aminolevulinicacids as active components and having excellentskin-beautifying effects such as prevention/amelioration of skinroughness, dry skin, wrinkles, sagging and flecks of skin, andimprovement of turnover of corneum; and an ameliorating effect on skindiseases such as atopic dermatitis.

Means for Attaining the Object

Conventionally known external preparations for head (hair restorers)containing 5-aminolevulinic acids as active components cannot be usedstably because of the following reasons: they cause damages to hair whenthey are not used in accordance with the direction of their dosage andadministration, resulting in problems such as split ends and a decreasein the number of hairs, and in addition, light shielding at the point ofuse is an absolute requirement. The present inventor has already foundthat these problems can be avoided by using 5-aminolevulinic acids andiron compounds in combination.

The present inventor has conducted a keen study and found out that amixture of 5-aminolevulinic acids and iron compounds have:skin-beautifying effects such as prevention/amelioration of skinroughness, dry skin, wrinkles, sagging and flecks of skin, andimprovement of turnover of corneum; and an ameliorating effect on skindiseases such as atopic dermatitis. The present invention has been thuscompleted.

In other words, the present invention relates to: (“1”) an externalpreparation for skin which contains one or more compounds selected fromthe group consisting of 5-aminolevulinic acid, its salt and a derivativeof them; and an iron compound; as active components; (“2”) the externalpreparation for skin according to (“1”) mentioned above, which furthercontains urea as an active component; and the (“3”) the externalpreparation for skin according to (“1”) or (“2”) mentioned above,wherein the iron compound is one or more compounds selected from thegroup consisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate.

The present invention also relates to: (“4”) a preventive/amelioratingdrug for skin roughness which contains one or more compounds selectedfrom the group consisting of 5-aminolevulinic acid, its salt and aderivative of them; and an iron compound; as active components; and(“5”) the preventive/ameliorating drug for skin roughness according to(“4”) mentioned above, wherein one or more compounds selected from thegroup consisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate, are used as an iron compound.

The present invention further relates to: (“6”) apreventive/ameliorating drug for dry skin which contains one or morecompounds selected from the group consisting of 5-aminolevulinic acid,its salt and a derivative of them; and an iron compound; as activecomponents; and (“7”) the preventive/ameliorating drug for dry skinaccording to (“6”) mentioned above, wherein one or more compoundsselected from the group consisting of ferrous citrate, iron sodiumcitrate, iron ammonium citrate, iron acetate, iron oxalate, ferroussuccinate, iron and sodium succinate citrate, ferrous pyrophosphate,ferric pyrophosphate, heme iron, iron dextran, iron lactate, ferrousgluconate, iron sodium diethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate, are used as an iron compound.

The present invention also relates to: (“8”) a preventive/amelioratingdrug for wrinkles/flecks which contains one or more compounds selectedfrom the group consisting of 5-aminolevulinic acid, its salt and aderivative of them; and an iron compound; as active components; and(“9”) the preventive/ameliorating drug for wrinkles/flecks according to(“8”) mentioned above, wherein one or more compounds selected from thegroup consisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate, are used as an iron compound.

The present invention further relates to: (“10”) a method forpreventing/ameliorating skin roughness comprising administeringtransdermally an external preparation for skin which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents.

The present invention also relates to: (“11”) a method forpreventing/ameliorating dry skin comprising administering transdermallyan external preparation for skin which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them; and an iron compound; as active components.

The present invention further relates to: (“12”) a method forpreventing/ameliorating wrinkles/flecks comprising administeringtransdermally an external preparation for skin which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents.

The present invention also relates to: (“13”) an ameliorating drug foratopic dermatitis which contains one or more compounds selected from thegroup consisting of 5-aminolevulinic acid, its salt and a derivative ofthem; and an iron compound; as active components; and (“14”) theameliorating drug for atopic dermatitis according to (“13”) mentionedabove, wherein one or more compounds selected from the group consistingof ferrous citrate, iron sodium citrate, iron ammonium citrate, ironacetate, iron oxalate, ferrous succinate, iron and sodium succinatecitrate, ferrous pyrophosphate, ferric pyrophosphate, heme iron, irondextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate, are used as an iron compound.

The present invention further relates to: (“15”) a method forameliorating atopic dermatitis comprising administering transdermally anexternal preparation for skin which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them; and an iron compound; as active components.

The present invention also relates to: (“16”) a set of externalpreparations for skin consisting of a first agent which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them, and a second agent whichcontains an iron compound; (“17”) the set of external preparations forskin according to (“16”) mentioned above, wherein the first agent and/orthe second agent further contain urea; and (“18”) the set of externalpreparations for skin according to (“16”) or (“17”) mentioned above,wherein the iron compound is one or more compounds selected from thegroup consisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and ammoniumdicarboxymethylglutamate.

The present invention further relates to: (“19”) a method forpreventing/ameliorating skin roughness comprising administeringtransdermally a first agent which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them, and a second agent which contains an ironcompound; (“20”) a method for preventing/ameliorating dry skincomprising administering transdermally a first agent which contains oneor more compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them, and a second agent whichcontains an iron compound; (“21”) a method for preventing/amelioratingwrinkles/flecks comprising administering transdermally a first agentwhich contains one or more compounds selected from the group consistingof 5-aminolevulinic acid, its salt and a derivative of them, and asecond agent which contains an iron compound; and (“22”) a method forameliorating atopic dermatitis comprising administering transdermally afirst agent which contains one or more compounds selected from the groupconsisting of 5-aminolevulinic acid, its salt and a derivative of them,and a second agent which contains an iron compound.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a photograph showing an example of clinical testing of anexternal preparation for skin of the present invention. The photographwas taken 5 days after the start of the treatment with the formulationexample 1. As to the treated cheek (the cheek on the left side of FIG.1), the skin became resilient and dry skin was ameliorated in comparisonto the cheek without treatment (the cheek on the right side of FIG. 1).In addition, the treated cheek (the cheek on the left side of FIG. 1)was lifted up in comparison to the cheek without treatment (the cheek onthe right side of FIG. 1).

FIG. 2 is a set of photographs showing an example of clinical testing ofan external preparation for skin of the present invention. The leftphotograph is a photograph of the face before the start of the treatmentwith the formulation example 1, and the right photograph is a photographof the face 14 days after the start of the treatment with theformulation example 1. After the treatment, the redness and thepigmentation of the affected area are ameliorated in comparison to thosebefore the treatment.

FIG. 3 is a set of photographs showing an example of clinical testing ofan external preparation for skin of the present invention. The leftphotograph is a photograph of the inside of the elbow before the startof the treatment with the formulation example 1, and the rightphotograph is a photograph of the inside of the elbow 7 days after thestart of the treatment with the formulation example 1. After thetreatment, the redness and pigmentation of the affected area areameliorated in comparison to those before the treatment, and theappearance of the skin is nearly normal.

FIG. 4 is a set of photographs showing an example of clinical testing ofan external preparation for skin of the present invention. The leftphotograph is a photograph of the underarm before the start of thetreatment with the formulation example 1, and the right photograph is aphotograph of the underarm 7 days after the start of the treatment withthe formulation example 1. After the treatment, the redness and thepigmentation of the affected area are ameliorated in comparison to thosebefore the treatment, and the appearance of the skin is nearly normal.In addition, no scratches are observed in the photograph after thetreatment because the itching subsided.

BEST MODE OF CARRYING OUT THE INVENTION

The external preparation for skin of the present invention is notparticularly limited as long as it contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them, and an iron compound, as active components.The above-mentioned 5-aminolevulinic acid is also referred to asδ-aminolevulinic acid, and is one of the amino acids shown by theformula HOOC—(CH₂)₂—(CO)—CH₂—NH₂ (hereinafter, also referred to as5-ALA). This 5-aminolevulinic acid is widely distributed in variousorganisms, and is generally biosynthesized by 5-aminolevulinic acidsynthetase from succinyl CoA and glycine. This 5-aminolevulinic acid isalso known as an intermediate of porphyrin biosynthesis.

Examples of salts of 5-aminolevulinic acid of the present inventioninclude acid addition salts such as hydrochloride, phosphate, nitrate,sulfate, acetate, propionate, butylate, valerate, citrate, fumarate,maleate, andmalate; and metal salts such as sodium salt, potassium salt,and calcium salt. It is preferred that these salts are used as aqueoussolutions, suspensions, or powders at the point of use, and have a sameeffect as that of 5-aminolevulinic acid.

As a representative embodiment of 5-aminolevulinic acid Derivatives usedas active components of the external preparation for skin and the set ofexternal preparations for skin of the present invention,5-aminolevulinic acid ester and N-acyl-5-aminolevulinic acid areexemplified. As an embodiment of 5-aminolevulinic acid ester, thefollowings are exemplified: optionally substituted linear, branched orcyclic alkyl ester having 1 to 24 carbon atoms, preferably, for example,an 5-aminolevulinic acid ester whose ester residue is a methyl group, anethyl group, an isopropyl group, an n-hexyl group, a cyclohexyl group,an n-heptyl group, an n-octyl group, an n-nonyl group, an n-dodecylgroup, an n-hexadecyl group, a benzyl group, a phenethyl group, a3-phenylpropyl group, a hydroxyethyl group, or an ethoxyethyl group. Inaddition, the followings are exemplified as a substituent of these alkylgroups: a hydroxyl group, an alkoxy group, a phenyl group, a benzylgroup, or a hydroxymethyl group. Further, as N-acyl-5-aminolevulinicacid, a compound wherein an amino group of 5-aminolevulinic acid isacylated with, for example, an alkanoyl group, an aromatic acyl group, abenzyloxycarbonyl group or the like, each having 1 to 24 carbon atoms isexemplified. Still further, as a preferred embodiment of an N-acylgroup, the followings are specifically exemplified: an acetyl group, ann-pentanoyl group, an n-hexanoyl group, an n-nonanoyl group, a benzoylgroup, and a benzyloxycarbonyl group.

The ester of 5-aminolevulinic acid and N-acyl-5-aminolevulinic acid canbe produced by publicly known chemical synthesis methods such as methodsdescribed in Japanese Laid-open Patent Application No. 4-9360, forexample. In addition to chemical synthesis, they can be produced byproduction methods either by microorganisms or by enzymes. Further, aroughly-purified product containing an object obtained in the process ofthe production can also be used without separation and purification aslong as the roughly-purified product does not contain a toxic substance.Each of 5-aminolevulinic acid, its salt, and their derivatives may beused alone, or by mixing two or more of them. The total amount of5-aminolevulinic acid, its salt, or a derivative of them contained inthe external preparation for skin of the present invention is usually0.01 to 40 wt %, preferably 0.1 to 10 wt % based on the whole of theexternal preparation for skin.

The iron compound in the present invention is not particularly limitedas long as it is a compound having iron in its molecule. Examples of theiron compound include ferrous citrate, iron sodium citrate, ironammonium citrate, iron acetate, iron oxalate, ferrous succinate, ironand sodium succinate citrate, ferrous pyrophosphate, ferricpyrophosphate, heme iron, iron dextran, iron lactate, ferrous gluconate,iron sodium diethylenetriaminepentaacetate, iron ammomiumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminetetraacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, ammonium dicarboxymethylglutamate,iron choline citrate, ferrous formate, ferric formate, ferric ammoniumpotassium oxalate, ferrous sulfate, ferric sulfate, iron ammoniumsulfate, ferric carbonate, ferrous chloride, ferric chloride, ferricpyrophosphate, and iron oxide. Among them, iron sodiumdiethylenetriaminepentaacetate and iron ammomiumdiethylenetriaminepentaacetate are preferred. Each of these ironcompounds may be used alone, or by mixing two or more of them. The totalamount of the iron compound contained in the external preparation forskin of the present invention is usually 0.01 to 80 wt %, preferably 0.5to 50 wt % based on the whole of the external preparation for skin.

The external preparation for skin of the present invention acts onsebaceous glands of the skin, and promote the secretion of sebum.Further, the external preparation for skin of the present invention actson epidermal cells and corneocytes, and activate these cells. It isconsidered that, as a result of that, it exerts skin-beautifying effectssuch as prevention/amelioration of skin roughness, dry skin, wrinkles,sagging and flecks of skin, and improvement of turnover of corneum.Therefore, the external preparation for skin of the present inventioncan be used as a preventive/ameliorating drug for skin roughness, apreventive/ameliorating drug for dry skin, and a preventive/amelioratingdrug for wrinkles/flecks. The term “preventive/ameliorating drug” in thepreventive/ameliorating drug for skin roughness, thepreventive/ameliorating drug for dry skin, and thepreventive/ameliorating drug for wrinkles/flecks of the presentinvention means “preventive and/or ameliorating drug”. In addition, theterm “wrinkles/flecks” of the present invention means “wrinkles and/orflecks”.

Further, the external preparation for skin of the present invention hasan ameliorating effect on skin diseases such as atopic dermatitis,eczema and dyskeratosis, as well. More specifically, it has anameliorating effect on dryness of the skin, pigmentation of the skin,itching of the skin, etc., caused by skin diseases such as atopicdermatitis, eczema and dyskeratosis. Therefore, the external preparationfor skin of the present invention can be used as an ameliorating drugfor the skin diseases such as atopic dermatitis, eczema anddyskeratosis.

With regard to the external preparation for skin of the presentinvention, it is not essential that urea is contained therein, however,those further containing urea as an active component are preferred. Ureais a colorless to white crystal or crystalline powder, and is freelysoluble in water, soluble in ethanol, and can be formed into many kindsof dosage forms such as lotions and creams, as external preparations. Inaddition, urea has a high affinity for the skin, and therefore, it has asuitable property as a component of external preparations for skin.Though it depends on the base material and other components used incombination, it is possible to blend urea into the external preparationfor skin of the present invention at a ratio of 0.01 to 40 (W/W %;weight ratio), preferably 0.1 to 10%. Commercially available urea can beused directly in applications.

The set of external preparations for skin of the present inventionconsists of a first agent which contains one or more compounds selectedfrom the group consisting of 5-aminolevulinic acid, its salt and aderivative of them, and a second agent which contains an iron compound.By separating the first agent containing 5-aminolevulinic acid, etc.,and the second agent containing an iron compound, the activity of5-aminolevulinic acid, etc. will last longer. Though the amount of5-aminolevulinic acid, its salt or a derivative of them contained in thefirst agent is not particularly limited, the total amount is usually0.01 to 40 wt %, preferably 0.1 to 10 wt % based on the whole of thefirst agent. Though the amount of the iron compound contained in thesecond agent is not particularly limited, the total amount is usually0.01 to 80 wt %, preferably 0.5 to 50 wt % based on the whole of thesecond agent.

Further, when the first agent and the second agent of the set ofexternal preparations for skin of the present invention are used incombination, a same effect as in the external preparation for skin ofthe present invention is obtained. Therefore, the set of externalpreparations for skin of the present invention can be used as a set ofpreventive/ameliorating drugs for skin roughness, a set ofpreventive/ameliorating drugs for dry skin, a set ofpreventive/ameliorating drugs for wrinkles/flecks, and a set ofameliorating drugs for skin diseases such as atopic dermatitis, eczemaand dyskeratosis.

With regard to the first agent and/or the second agent of a set ofexternal preparations for skin of the present invention, it is notessential that urea is further contained therein, however, it ispreferred that urea is further contained therein. The amount of ureacontained in the first agent and the second agent is not particularlylimited, and it is possible to blend urea at a ratio of 0.01 to 40 (W/W%; weight ratio), preferably 0.1 to 10%.

In addition to 5-aminolevulinic acid, its salt or a derivative of them,an iron compound and urea mentioned above, one or more of variouscomponents commonly used in pharmaceuticals and cosmetics, in otherwords, aqueous components, oily components, powdery components, chemicalagents such as surface active agents, moisturizing agents, thickeners,colorants, fragrances, pH adjusters, antioxidants, antiseptics, or UVprotectants, and anti-inflammatory agents can be blended into theexternal preparation for skin of the present invention, and the firstagent and the second agent of the set of external preparations for skinof the present invention, to the extent that they do not damage theeffect of the present invention.

As aqueous components, for example, water, lower alcohol (methanol,ethanol, denatured ethanol, propanol, isopropyl alcohol), etc., areexemplified.

As the oily components, for example, higher fatty acids (stearic acid,palmitic acid, myristic acid, lauric acid and esters thereof, etc.),higher alcohols (cetanol, lanolin alcohol, stearyl alcohol, cetostearylalcohol, etc.) and waxes (hard paraffin, microcrystalline wax, ceresinwax, polyethylene wax, beeswax, Japan wax, carnauba wax, candelilla wax,etc.), natural or synthetic oily substances (squalane, liquid paraffin,lanolin or derivatives thereof, olive oil, camellia oil, cottonseed oil,oleyl alcohol, castor oil, Vaseline, diethoxyethyl adipate ester,silicon oil, fluorine oil, etc.) are exemplified.

As powdery components, for example, aluminum powders, titanium oxidepowders, zinc oxide powders, iron oxide powders, acrylic powders, silicabeads, talc, sericite, etc., are exemplified.

As surface active agents, for example, sorbitan fatty acid ester,glycerine fatty acid ester, polyglycerine fatty acid ester, propyleneglycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester,polyoxyethylene sorbit fatty acid ester, polyoxyethylene glycerine fattyacid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkylether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylenealkylphenyl ether, polyoxyethylene hydrogenated castor oil,polyoxyethylene castor oil, polyoxyethylene beeswax derivatives,polyoxyethylene lanolin derivatives, polyoxyethylene alkylamide,polyoxyethylene alkylamine, lecithin derivatives, polymeric emulsifiers,etc., are exemplified.

As moisturizing agents, for example, polyhydric alcohols such asglycerine, propylene glycol, 1,3-butylene glycol, dipropylene glycol,ethylene glycol, 1,4-butylene glycol, diglycerine, triglycerine, sorbitor derivatives thereof, polyethylene glycol, etc.; and glucose, maltose,maltitol, sucrose, fructose, threitol, erythritol, sorbit,starch-degraded sugar, hyaluronic acid, chondroitin sulfate, hydrolyzedcollagen, hydrolyzed elastin, carboxymethyl chitin, casein soda, muchin,glycosphingolipid, etc., are exemplified.

As thickeners, for example, carboxyvinyl polymer, CP jelly,carboxymethyl cellulose, carageenan, sodium alginate, bentonite, veegum,synthetic hectorite, etc., are exemplified.

As antioxidants, for example, butylated hydroxytoluene (BHT), butylatedhydroxyanisole (BHA), sodium pyrosulfite, sodium bisulfate, tocopherol,sodium edetate, ascorbic acid, isopropyl gallate, etc., are exemplified.

As pH adjusters, for example, citric acid, lactic acid, tartaric acid,phosphoric acid, etc., are exemplified.

As antihistamines, for example, diphenhydramine hydrochloride,isothipendyl hydrochloride, etc., are exemplified.

As antiseptics, for example, methyl, ethyl, propyl, and butyl esters ofp-hydroxybenzoic acid, phenoxyethanol, o-phenylphenol, dehydroaceticacid or salts thereof, p-cresol, m-cresol, o-chlor-m-xylenol, etc., areexemplified.

As UV protectants, for example, ascorbic acid or derivatives thereof,isoferulic acid or salts thereof, oxybenzone or derivatives thereof,p-aminobenzoic acid or derivatives thereof, urocanic acid or derivativesthereof, kojic acid, dibenzoyl methane or derivatives thereof,p-methoxycinnamic acid or derivatives thereof, particulate titaniumoxide, particulate zinc oxide, particulate iron oxide, etc., areexemplified.

As anti-inflammatory agents, for example, glycyrrhetinic acid orderivatives thereof, glycyrrhizinic acid or derivatives thereof,guaiazulene or derivatives thereof, bisabolol, geraniin, horse chestnutextracts, aloe extracts, etc., are exemplified.

Each of the components and the chemical agents mentioned above can beused alone, or by mixing two or more of them.

With regard to the dosage form of an external preparation for skin ofthe present invention, and of the first agent and the second agent ofthe set of external preparations for skin of the present invention, anyform of powders, liquids and ointments can be employed. Dosage formssuch as lotions, emulsions, creams (ointments), gels, and aerosols canbe prepared, according to methods usually used (for example, methodsprescribed in The Japanese Pharmacopoeia 12^(th) Edition). Further, theexternal preparation for skin of the present invention may beliposomally encapsulated. Methods for liposomal encapsulation are notparticularly limited, and are described, for example, in JapaneseLaid-open Patent Application No. 11-199488, etc.

When prepared as aqueous solutions such as lotions, or creams(ointments), in order to prevent degradation of 5-aminolevulinic acid orits salt or a derivative of them, it is preferred to prepare theexternal preparation for skin while paying attention not to causealkalinization. In case of alkalinization, degradation can be preventedby removing oxygen. Paying attention to this, 5-aminolevulinic acid orits salt or a derivative of them can be used in combination withcomponents of liquids or ointments usually used.

Though there is no particular limitation to the method for using anexternal preparation for skin of the present invention, it is preferredthat the external preparation for skin of the present invention istransdermally administered to the skin by methods such as spraying,application, or a poultice. In addition, transdermal administrationusing a drug delivery system such as iontophoresis is preferred becauseit promotes the speed of drug absorption into skin tissues and increasesthe ratio of drug absorption, as well.

There is no particular limitation to the method for using a set ofexternal preparations for skin of the present invention, and thefollowing methods can be adapted: a method comprising mixing the firstagent and the second agent together, and applying the mixture to theskin; a method comprising applying the first agent and the second agentto the skin at the same time; a method comprising applying the firstagent to the skin and then applying the second agent to the same part;and a method comprising the second agent to the skin and then applyingthe first agent to the same part. Further, though the method comprisingadministering the first agent and the second agent is not particularlylimited, methods such as spraying, application, or a poultice to theskin, or methods using a drug delivery system such as iontophoresis arepreferred.

With regard to the dosage of the external preparation for skin of thepresent invention, and the first agent and the second agent of the setof external preparations for skin of the present invention, there is noparticular limitation as long as it is a level exerting an effect onskin roughness etc. However, in case of application to the skin, it ispreferred to administer the external preparation for skin such that5-aminolevulinic acid or its salt and a derivative of them isadministered in an amount of 10 μg to 10 mg, desirably 100 μg to 5 mg,more desirably 1 mg to 5 mg per 10 cm² of skin, in 5-aminolevulinic acidhydrochloride equivalent. The dosage of iron compounds to be combinedwith 5-aminolevulinic acid, etc., is 50 μg to 50 mg, desirably 500 μg to25 mg, more desirably 5 mg to 25 mg, in iron equivalent under the sameconditions.

As an administration form of the external preparation for skin of thepresent invention, and of the first agent and the second agent of theset of external preparations for skin of the present invention, thefollowing method is preferably exemplified but not limited thereto: amethod comprising administering transdermally the external preparationfor skin of the present invention, or the first agent and the secondagent of the set of external preparations for skin of the presentinvention from the twilight to the night by methods such as application,and rinsing off in the same night.

One characteristic of the external preparation for skin and the set ofexternal preparations for skin of the present invention resides in thepoint that there is no need for a strict light shielding treatment,which is necessary when 5-aminolevulinic acid is administered(application, etc.) alone. However, it is preferred to avoid beingexposed to strong light, for example, being in a scorching sun. With theuse of the external preparation for skin and the set of externalpreparations for skin of the present invention, in many cases,skin-beautifying effects such as amelioration of skin roughness, dryskin, wrinkles, sagging and flecks of skin, and improvement of turnoverof corneum, and an ameliorating effect on skin diseases such as atopicdermatitis are seen from day 3. In case the effects reach a plateau, theeffects can be expected again by stopping the administration once andresuming the administration 3 months later, though the externalpreparation for skin and the set of external preparations for skin ofthe present invention can be used continuously.

The methods of the present invention are: a method forpreventing/ameliorating skin roughness comprising administeringtransdermally an external preparation for skin which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents; a method for preventing/ameliorating dry skin comprisingadministering transdermally an external preparation for skin whichcontains one or more compounds selected from the group consisting of5-aminolevulinic acid, its salt and a derivative of them; and an ironcompound; as active components; a method for preventing/amelioratingwrinkles/flecks comprising administering transdermally an externalpreparation for skin which contains one or more compounds selected fromthe group consisting of 5-aminolevulinic acid, its salt and a derivativeof them; and an iron compound; as active components; a method forameliorating atopic dermatitis comprising administering transdermally anexternal preparation for skin which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them; and an iron compound; as active components; amethod for preventing/ameliorating skin roughness comprisingadministering transdermally a first agent which contains one or morecompounds selected from the group consisting of 5-aminolevulinic acid,its salt and a derivative of them, and a second agent which contains aniron compound; a method for preventing/ameliorating dry skin comprisingadministering transdermally a first agent which contains one or morecompounds selected from the group consisting of 5-aminolevulinic acid,its salt and a derivative of them, and a second agent which contains aniron compound; a method for preventing/ameliorating wrinkles/fleckscomprising administering transdermally a first agent which contains oneor more compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them, and a second agent whichcontains an iron compound; and a method for ameliorating atopicdermatitis comprising administering transdermally a first agent whichcontains one or more compounds selected from the group consisting of5-aminolevulinic acid, its salt and a derivative of them, and a secondagent which contains an iron compound. There is no particular limitationto the method for transdermally administering the first agent and thesecond agent mentioned above, and the following methods can be adapted:a method comprising mixing the first agent and the second agenttogether, and applying the mixture to the skin; a method comprisingapplying the first agent and the second agent to the skin at the sametime; a method comprising applying the first agent to the skin andapplying the second agent to the same part; and a method comprisingapplying the second agent to the skin and then applying the first agentto the same part.

The present invention will be described more specifically with referenceto the Examples, however, the technical scope of the present inventionis not limited to these exemplifications.

EXAMPLE 1

1.5 g of 5-aminolevulinic acid hydrochloride, 3 g of urea and 1 g offerrous citrate were mixed well into 20 ml of purified water in which 4%of 1,3-butylene glycol and 0.15% of methylparaben had been dissolved, toprepare the formulation example 1 was prepared.

About 2 ml of the formulation example 1 was applied every night to facesof subjects (8 adult women). After application, the faces were left for30 minutes to 1 hour, and then the faces were washed in the same night,to rinse off the formulation example.

The conventional strict light shielding conditions, applied when5-aminolevulinic acids are used alone, were not performed, and hairremoval occurring when the dosage is partially excessive was notobserved. The formulation example 1 was evaluated 5 days after the startof the application by each of 8 subjects. The results are shown below.

Subject 1: only the right half of the face was treated with theformulation example 1, and the skin at the treated part became resilientand the dryness was ameliorated. In addition, the treated cheek (thecheek on the left side of FIG. 1) was lifted up in comparison to thecheek without treatment.Subject 2: the skin became resilient. The nasolabial folds that run fromthe nose to the both sides of the mouth became less prominent. When theformulation example 1 was being applied longer, the secretion of sebumincreased, and dry skin was ameliorated. Makeup was put on in a betterstate.Subject 3: the skin became resilient. The nasolabial folds became lessprominent. Crow's feet disappeared. Makeup was put on in a better state.Subject 4: the skin became resilient. The complexion became fairer.

Subject 5: the skin became resilient. Dry skin was ameliorated. Makeupwas put on in a better state.

Subject 6: the skin became resilient. The skin became moisturized.Subject 7: there was no special change.Subject 8: there was no special change.

As described above, 6 out of 8 subjects noticed subjective symptomsshowing amelioration of skin condition, for example, skin resilience. Asit can be seen from the comment of subject 2, the external preparationfor skin of the present invention has an effect on promoting thesecretion of sebum, and it is considered that, as a result of that, itexerts effects on improving skin resilience, ameliorating dry skin, andmaking nasolabial folds less prominent, etc. With regard to subject 1,who is a patient of atopic dermatitis, the skin became resilient and thedryness was ameliorated. Consequently, it is suggested that the externalpreparation for skin of the present invention is also effective forprevention/amelioration of skin roughness, dry skin, wrinkles, andsagging of skin resulted from atopic dermatitis. In addition, an effecton making complexion fairer, as in the case of subject 4, was observedas well.

EXAMPLE 2

The formulation example 1 in Example 1 was applied once every night toaffected areas of 6 patients of atopic dermatitis (subjects 9 to 13; andsubject 1 in Example 1), and 2 patients of chronic eczema (subjects 14to 15) in an amount of about 1 ml per 100 cm² of skin. Afterapplication, the affected areas were left for 30 minutes to 1 hour, andthen the areas to which the formulation example 1 was applied werewashed in the same night to rinse off the formulation example. Theaffected areas, 1, 2 weeks after the start of the administration of theformulation example 1, were compared with the affected areas before theadministration, and the judgment and the evaluation of “markedlyameliorated” “ameliorated” “no change” and “worsened” were conducted bythe inventor, who is a doctor. The judgment and evaluation wereconducted using the levels of amelioration of redness, pigmentation anditching of the skin, and the level of softening of the skin, as anindicator. As a result, 4 out of 6 patients of atopic dermatitis were“markedly ameliorated” and the other 2 patients were “ameliorated”, andlout of 2 patients of chronic eczema was “markedly ameliorated” and theother patient was “ameliorated”. Based on this result, it is shown thatthe external preparation for skin of the present invention amelioratesnot only atopic dermatitis but also skin conditions such as eczema anddyskeratosis.

Hereinafter, 3 out of 8 patients of atopic dermatitis will be describedin more detail.

Subject 1: “ameliorated”

Subject 1 has been suffering from atopic dermatitis. Only the right halfof the face was treated with the formulation example 1, and the skin atthe treated part became resilient and the dryness was ameliorated. Inaddition, the skin at the treated part became soft and the treated cheekwas lifted up in comparison to the cheek without treatment.

Subject 9: “markedly ameliorated”

Subject 9 has been suffering from atopic dermatitis since elementaryschool, and has been using external preparations of steroidintermittently for several decades. Major affected areas are the faceand neck. In the affected areas, the skin was hard and exhibited rednessand pigmentation (see FIG. 2, the left photograph of the face), and wasaccompanied by itching, and a typical atopy-like appearance wasobserved. Subject 9 was instructed to use the formulation example 1together with an external preparation of steroid, and 3 days later, theexternal preparation of steroid was discontinued because the itchingdisappeared. After that, only the formulation example 1 was used, andthe redness and pigmentation in the affected areas were ameliorated, andthe skin became soft (see FIG. 2, the right photograph of the face).Further, the conditions of wrinkles and flecks of the skin were alsoameliorated.

Subject 10: “markedly ameliorated”

Subject 10 has been suffering from atopic dermatitis since elementaryschool, and has been using external preparations of steroidintermittently for several decades. Major affected areas are theunderarm and inside of the elbow. In the affected areas, there wasitching, and the skin was hard and exhibited redness, pigmentation andscratches [see the left photographs of FIG. 3 (the inside of the elbow)and FIG. 4 (the underarm)], and a typical atopy-like appearance wasobserved. Subject 10 was instructed to use the formulation example 1together with an external preparation of steroid, and 3 days later, theexternal preparation of steroid was discontinued because the itchingdisappeared. After that, only the formulation example 1 was used, andthe redness and pigmentation in the affected areas were ameliorated, theskin became soft and the appearance of the skin became nearly normal[see the right photographs of FIG. 3 (the inside of the elbow) and FIG.4 (the underarm)].

INDUSTRIAL APPLICABILITY

The external preparation for skin of the present invention whichcontains 5-aminolevulinic acids has skin-beautifying effects such asprevention/amelioration of skin roughness, dry skin, wrinkles, saggingand flecks of skin, and improvement of turnover of corneum; and anameliorating effect on dermatitis such as atopic dermatitis. Further, as5-aminolevulinic acids and an iron compound are used in combination inthe external preparation for skin of the present invention, lightshielding at the point of use is not an absolute requirement for theexternal preparation for skin of the present invention and its usage issimple. Moreover, with regard to the skin-beautifying effects such asprevention/amelioration of skin roughness, dry skin, wrinkles, saggingand flecks of skin, and improvement of turnover of corneum; and theameliorating effect on skin diseases such as atopic dermatitis, theexternal preparation for skin of the present invention exhibits aremarkable effect equal to or stronger than the effect observed when5-aminolevulinic acids are used alone.

1. An external preparation for skin which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them; and an iron compound; as active components. 2.The external preparation for skin according to claim 1, which furthercontains urea as an active component.
 3. The external preparation forskin according to claim 1 or 2, wherein the iron compound is one or morecompounds selected from the group consisting of ferrous citrate, ironsodium citrate, iron ammonium citrate, iron acetate, iron oxalate,ferrous succinate, iron and sodium succinate citrate, ferrouspyrophosphate, ferric pyrophosphate, heme iron, iron dextran, ironlactate, ferrous gluconate, iron sodium diethylenetriaminepentaacetate,iron ammonium diethylenetriaminepentaacetate, iron sodiumethylenediaminetetraacetate, iron ammonium ethylenediaminepentaacetate,iron triethylenetetraamine, iron sodium dicarboxymethylglutamate, andiron ammonium dicarboxymethylglutamate.
 4. A preventive/amelioratingdrug for skin roughness which contains one or more compounds selectedfrom the group consisting of 5-aminolevulinic acid, its salt and aderivative of them; and an iron compound; as active components.
 5. Thepreventive/ameliorating drug for skin roughness according to claim 4,wherein one or more compounds selected from the group consisting offerrous citrate, iron sodium citrate, iron ammonium citrate, ironacetate, iron oxalate, ferrous succinate, iron and sodium succinatecitrate, ferrous pyrophosphate, ferric pyrophosphate, heme iron, irondextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and iron ammoniumdicarboxymethylglutamate, are used as an iron compound.
 6. Apreventive/ameliorating drug for dry skin which contains one or morecompounds selected from the group consisting of 5-aminolevulinic acid,its salt and a derivative of them; and an iron compound; as activecomponents.
 7. The preventive/ameliorating drug for dry skin accordingto claim 6, wherein one or more compounds selected from the groupconsisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and iron ammoniumdicarboxymethylglutamate, are used as an iron compound.
 8. Apreventive/ameliorating drug for wrinkles/flecks which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents.
 9. The preventive/ameliorating drug for wrinkles/flecksaccording to claim 8, wherein one or more compounds selected from thegroup consisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and iron ammoniumdicarboxymethylglutamate, are used as an iron compound.
 10. A method forpreventing/ameliorating skin roughness comprising administeringtransdermally an external preparation for skin which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents.
 11. A method for preventing/ameliorating dry skin comprisingadministering transdermally an external preparation for skin whichcontains one or more compounds selected from the group consisting of5-aminolevulinic acid, its salt and a derivative of them; and an ironcompound; as active components.
 12. A method for preventing/amelioratingwrinkles/flecks comprising administering transdermally an externalpreparation for skin which contains one or more compounds selected fromthe group consisting of 5-aminolevulinic acid, its salt and a derivativeof them; and an iron compound; as active components.
 13. An amelioratingdrug for atopic dermatitis which contains one or more compounds selectedfrom the group consisting of 5-aminolevulinic acid, its salt and aderivative of them; and an iron compound; as active components.
 14. Theameliorating drug for atopic dermatitis according to claim 13, whereinone or more compounds selected from the group consisting of ferrouscitrate, iron sodium citrate, iron ammonium citrate, iron acetate, ironoxalate, ferrous succinate, iron and sodium succinate citrate, ferrouspyrophosphate, ferric pyrophosphate, heme iron, iron dextran, ironlactate, ferrous gluconate, iron sodium diethylenetriaminepentaacetate,iron ammonium diethylenetriaminepentaacetate, iron sodiumethylenediaminetetraacetate, iron ammonium ethylenediaminepentaacetate,iron triethylenetetraamine, iron sodium dicarboxymethylglutamate, andiron ammonium dicarboxymethylglutamate, are used as an iron compound.15. A method for ameliorating atopic dermatitis comprising administeringtransdermally an external preparation for skin which contains one ormore compounds selected from the group consisting of 5-aminolevulinicacid, its salt and a derivative of them; and an iron compound; as activecomponents.
 16. A set of external preparations for skin consisting of afirst agent which contains one or more compounds selected from the groupconsisting of 5-aminolevulinic acid, its salt and a derivative of them,and a second agent which contains an iron compound.
 17. The set ofexternal preparations for skin according to claim 16, wherein the firstagent and/or the second agent further contain urea.
 18. The set ofexternal preparations for skin according to claim 16 or 17, wherein theiron compound is one or more compounds selected from the groupconsisting of ferrous citrate, iron sodium citrate, iron ammoniumcitrate, iron acetate, iron oxalate, ferrous succinate, iron and sodiumsuccinate citrate, ferrous pyrophosphate, ferric pyrophosphate, hemeiron, iron dextran, iron lactate, ferrous gluconate, iron sodiumdiethylenetriaminepentaacetate, iron ammoniumdiethylenetriaminepentaacetate, iron sodium ethylenediaminetetraacetate,iron ammonium ethylenediaminepentaacetate, iron triethylenetetraamine,iron sodium dicarboxymethylglutamate, and iron ammoniumdicarboxymethylglutamate.
 19. A method for preventing/ameliorating skinroughness comprising administering transdermally a first agent whichcontains one or more compounds selected from the group consisting of5-aminolevulinic acid, its salt and a derivative of them, and a secondagent which contains an iron compound.
 20. A method forpreventing/ameliorating dry skin comprising administering transdermallya first agent which contains one or more compounds selected from thegroup consisting of 5-aminolevulinic acid, its salt and a derivative ofthem, and a second agent which contains an iron compound.
 21. A methodfor preventing/ameliorating wrinkles/flecks comprising administeringtransdermally a first agent which contains one or more compoundsselected from the group consisting of 5-aminolevulinic acid, its saltand a derivative of them, and a second agent which contains an ironcompound.
 22. A method for ameliorating atopic dermatitis comprisingadministering transdermally a first agent which contains one or morecompounds selected from the group consisting of 5-aminolevulinic acid,its salt and a derivative of them, and a second agent which contains aniron compound.